Sam is right: long, fast trips are good for the car. Just make sure the engine and gearbox are thoroughly warmed up before taking the car much above 3,000rpm. 10 to 15 miles should be more than enough to get everything up to temperature.

However, short trips in urban conditions are bad for the car. This is because the engine never gets warmed up. It is always starting or running cold (which is inherently bad for the engine). Also, stop-start urban traffic places higher stresses on the components than even high speed steady cruising.

I did 2,200 miles in 3 days in my C240 last summer, running at very high speed for extended periods (mostly 100mph plus). When I returned home I took the car straight to the dealer to ask if he should have a look at it, maybe change the oil and filter. "Absolutely not," he said, "the car will have enjoyed it."

Now, given how keen dealers usually are to do unnecessary work and generally take advantage of the naive punter, his words must be true!

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JJ Rodger
2013 G350 Bluetec
1999 SL 500
1993 E300 diesel T
1990 190